Recently, as molecular biology has been rapidly developed, a genetic diagnosis technology has been developed more rapidly than a diagnosis using an antigen-antibody reaction or a biomolecular interaction.
The genetic diagnosis technology requires DNA replication and amplification for a rapid diagnosis. Kary Mullis, who is a biochemist in U.S.A., has proposed a PCR (Polymerase Chain Reaction) as one method for DNA replication and amplification.
Three steps of DNA denaturation, annealing and elongation are required to cause the PCR.
A thermal source is necessarily required since the higher temperature than the normal temperature must be maintained for the denaturation, annealing and elongation steps.
The thermal source for heating DNA may be classified into a contact type in which the thermal source makes direct contact with a sample chamber and a non-contact type in which the thermal source does not make direct contact with a sample chamber.
The contact type thermal source includes a heater using a Peltier device or resistance heat and the non-contact type thermal source utilizes near infrared ray, far infrared ray, hot air, or a magnetron as the thermal source.
The contact type thermal source indirectly heats the DNA received in a sample chamber by allowing the sample chamber to make contact with a heating block including a Peltier device or a resistance device, so that additional time is taken to transfer heat from the heating block serving as the thermal source to the DNA.
Meanwhile, in the non-contact type thermal source, the DNA received in the sample chamber is directed heated without making contact with a heat transfer medium. Since air is heated when hot air is used, a space for making the hot air is required. In a case of magnetron, a high frequency corresponding to a resonant frequency of water is generated to heat a target. In this case, although the target is heated at a high speed, a metal material which may exert a bad influence on the resonant frequency is not used around the thermal source, a large space for heating the target is required and an electromagnetic wave harmful to the human body is radiated.
In addition, although the target may be rapidly heated to the target temperature at a high speed and may be directly heated without an intermediate heat transfer medium when the infrared ray is used, time for changing the temperature of the heat source is required and the infrared ray is absorbed into most materials.
A high speed gene amplification apparatus for causing a PCR using the infrared ray according to the related art is disclosed in US patent publication No. 2005/0287661. The amplification apparatus disclosed in the above patent document uses a single heat source to control the temperatures corresponding to the denaturation, annealing and elongation steps in the same chamber.
However, since the gene amplification apparatus for causing the PCR according to the related art uses the single heat source, a considerable amount of time is spent until the temperature of the sample chamber heated at the high temperature drops.
In addition, since the signal heat source is used, the temperature is not actively changed corresponding to each step, so it is impossible to amplify a plurality of gene samples in various conditions.